Flow resistance of modular geosynthetic materials used for conveyance in stormwater source control

Todorovic, Z

Abstract

Growing demand for sustainable urban drainage systems (SUDS) to
limit run-off has opened new areas of research into the application of
plastic materials to form underground voids that are used either to
attenuate (built in layers of boxes as tanks), or to convey storm water
(laid down in rows as panels). This solution replaces the more expensive
use of holes filled with gravel and crushed stones. Although a limited
number of flow experiments had previously been carried out on thin
geocomposite materials, there was no prior research into the panel of
boxes used in SUDS. This thesis presents results of a programme of
laboratory tests performed to investigate the hydraulic capacities of a
panel of boxes for lateral conveyance of stormwater. The results
highlighted two design cases, *box' structures where voids in the boxes
are unfilled and blocks' structures where the voids are filled with
granular material. A physical based mathematical model to simulate
the flow through either type of structure is presented in the thesis.
The computer model developed from the laboratory studies is a
'compartment model' comprising two main components. In zone 1
calculations are performed for gradual losses in hydraulic conditions
that range from open channel flow to the flow through porous media.
The modified Manning's equation, or Izbach's exponential equation are
both used depending upon the flow type. In zone 2 the orifice equation
is used to calculate local losses at the end of each box. A set of three
unique calibration parameters is required for each type of material.
Close correlation between measured and calculated data confirmed that
the theory was the appropriate one to describe the flow through
different types of geosynthetic panel of materials with varying number
of boxes in height, width and length and ranging from highly voided
boxes, to more dense grids filled with different types of aggregates.

Citation

Todorovic, Z. Flow resistance of modular geosynthetic materials used for conveyance in stormwater source control. (Thesis). Salford : University of Salford

• Thesis Type: Thesis
• Deposit Date: Oct 3, 2012
• Award Date: Jan 1, 2003